It's risk shifting. GM has almost certainly forced some subcontractor to bear the risk of holding the required inventory for the legally required repair period

It's risk shifting. GM has almost certainly forced some subcontractor to bear the risk of holding the required inventory for the legally required repair period. That subcontractor worked out the cost per item to be able to do this--especially for something qualified as a safety system. This price has very little to do with material cost and everything to do with outsourcing.